1. Field of the Invention
The present invention generally relates to optical devices. More particularly, the invention relates to packaging for optoelectronic devices.
2. Description of the Related Art
An optoelectronic device is a device that is configured to promote the interconversion of electricity and light. One example of an optoelectronic device is an electro-optical modulator. In order to protect the optoelectronic device from the surrounding environment, the optoelectronic device is typically disposed in a sealed housing or a package.
Conventionally, the package for the optoelectronic device is made from a high-cost hermetic metal material or a ceramic material. The package includes electrical connections through a wall of the package. The electrical connections are made by a ceramic feedthrough or a glass to metal seal around a coaxial connector in order to bring an electrical signal to the electrodes of the optoelectronic device. The electrical connections from a conductor pin or a connector on the package to the electrodes on a chip of the optoelectronic device are either made by directly soldering to the pin or by ceramic strip lines.
The package is also configured to allow optical fibers to pass through a wall of the package. For a hermetic package, a seal between the package wall and the optical fibers must be established and maintained. The optical fibers provide an optical feed through to the optoelectronic device. The optical fibers are generally fixed to the chip in the optoelectronic device by means of fiber-blocks and UV curable adhesive in order to transmit the optical signal through the optical waveguides in the chip. The chip in the optoelectronic device is typically fixed directly onto a base of the package or onto a submount fixed to the base of the package with a face-up or a flip chip technique.
In addition to the conventional metal or ceramic packages for the optoelectronic device, the package may also be made from a plastic material. Similar to the conventional packages, the plastic package includes electrical connections through a wall of the package and optical feed throughs. Although the plastic package provides a tangible cost reduction relative to the conventional packages, the plastic package requires the use of a material, such as silicon, to encapsulate the optoelectronic device in order to protect the device from moisture. The use of the material (silicon) in the plastic package, however, reduces the performance of the optoelectronic device. For instance, an optoelectronic device disposed in a plastic package and encapsulated by silicon does not have acceptable performance beyond 2.5 GHz.
As the foregoing illustrates, there is a need in the art for a plastic module package that is configured to allow the optoelectronic device to perform at a higher bandwidth than the prior art appreciates.